When accessing the database for CONCURRENT RETRIEVAL, we sometimes receive the following fatal error:

DBM-F-FILACCERR, error opening storage area file <str>; -SYSTEM-W-ACCONFLICT, file access conflict.

There were no other processes accessing this database when the error occurs. This problem seems to occur more frequently during the evening hours.

On the basis of our analysis, the problem you are experiencing is a conflict with the VMS system BACKUP. This would explain why you are seeing the problem more frequently during the evening (when your backups are scheduled).

First, you should make absolutely certain that you are not using VMS backup to backup your Rdb or DBMS database (see Backup article in this issue). Use the RMU/BACKUP (for Rdb) or DBO/BACKUP (for DBMS) utility to backup your database. Next, you should ask your system manager to exclude all database backups from the VMS system backup (/EXCLUDE= *.DBS,*.ROO,*.RDA,*.RDB,*.SNP). In addition, SCI recommends that customers use the DCL COMMAND SET FILE/NOBACKUP to ensure that database files are not accidentally backed (and restored) by the system backup and restore procedures. If you attempt to use VMS to restore a file that was marked "/NOBACKUP", the error will be obvious – an empty file will be restored (VMS will backup the header of files marked with /NOBACKUP). Always use the RMU/BACKUP and RMU/RESTORE or DBO/BACKUP and DBO/RESTORE routines to backup and restore your databases!